Gael otto gehrckens



Patented uw. x7, Ism.

4. o. sencxens.

nalvme BELT.

(Applieltilm'hd In. 18, 1901.)

(lin lodel.)

' Zig] UNITED STATES PATENT rrrcn.

CARL OTTO GEHRCKENS, OFHAMBURG, GERMANY.

DRIVING-BELT.

SPECIFICATION forming part of Letters Patent N o. 689,178, dated December 17, 1901.

l Application iled March 18, 1901l Serial No. 51,692. (No model.)

T0 all whom it may concern.:

Be it known that 1, CARL GTTO GEHReKnNs, a subject of the German Emperor, and a resident of Hamburg, in the German Empire,have invented certain new and useful Improvements in Driving-Belts, of which the following is a specification.

The present invention relates to improvements in driving-belts, especially ofthat class which have becomeknown by the specification of my prior United States Patent, No. 324,993, of August 25, 1885, and which cousists of two or more longitudinal strips having equal or nearly-equal breadth and being superposed or placed in the form of steps or stairs one upon the other, so that the overlapping or the projecting parts (the steps or lags) of the several strips are of practically equal width, the layers being connected by cementing, sewing, or any other suitable means. Driving-belts of this kind have proved very true and advantageous, especially when used as quartered belts. In quartered belts, as is well known, the belt on leaving the driving-pulley turns or cants on its stretched or longer edge, so that its other or shorter edge is canted or turned away from the drivingpulley. This outward turning or canting of the belt continues until the belt reaches the driven pulley, where the belt is in a plane at about right angles to the plane or position in which it leaves the driving pulley. The canted or turned-oli or longer edge of the belt has therefore to travel a greater distance than the edge on which the belt is turning or canting. For this reason and for the reason that the latter edge of the belt is nearer 4to the imaginary crossing-point of the shafts of the pulleys this edge is com mouly called inner edge, whereas the other edge is generally known as outer edge of the belt. Quartered belts of the above-described construction frst assist Ythe outer edge of the belt on leaving the pulley to lift or move off therefrom,and 'to thereby cause the belt to assume an oblique position to the pulley, so as to form at this place a sort of bell-mouthed or funnel-shaped bag, (which peculiar formation of the belt is absolutely necessary for compensating :for the surplus or excess of travel of the outer edge over that of the inner edge of the belt,) and, secondly, they reliably prevent the edges of the belt from overstretching, and consequently from lateral breakage or tearing, because in such step or stair shaped belts the line of greatest tension is removed from the edge to a line nearer to the middle of the belt. In spite of the abovementioned advantages the said stepped belts yet possess the disadvantage that they do not allow the belt in its own plane to form an arch or annular segment, or at least render this difiicult. Quartered belting is known to stretch more on the outer edge than on the inner edge. In consequence of this fact there is the tendency in quartered belts to shape themselves by this very surplus stretching of the outer edge into an arch-shaped or segmental band form, the inner edge of such a belt being more curved than the outer one.

The belt must therefore be eapableof taking the said curved form without breaking or tearing at the outer edge-that is, that one having the longer radius.

The object of the presentimprovements is to construct, arrange, and connect the longitudinal strips in such a manner that the step or stair shaped belt without altering its abovementioned advantages (formation of a funnel or bell shaped bag and prevention of lateral breakage) is adapted to accept the necessary arch shape or segmental form at the turn in an easier and more natural manner. The object aimed at is atta-ined by making the longitudinal strips to be superposed not of equal, but of unequal, breadth, increasing each by at least one-third in breadth, so that Vthe outer edge of the stair-shaped or stepped belt receives a proportionately greater lag than the inner edge.

In theaccompanying drawings, Figure lis a plan view, and Fig. 2 a cross-section, of a portion of an improved driving-belt embodying my invention. Fig. 3 is a plan view of the same driving-belt after use, having taken an arch-shaped or seg mental band form. Fig. 4 is a plan View, and Fig. 5 a cross-section, showing a modification of my improved driving-belt.

Similar letters referto similar parts throughout the several figures.

Referring to Figs. l and 2, my improved IOO driving-belt consists of a strip ct and a strip b, superposed upon and connected Awith each other in any suitable manner. The strip ct is 4by one-third or about sor much broader than the strip b, thus insuring a greater lag at the outer edge. This greater lag at the outer edge allows a greater' stretching and extension of the belt along this outer edge than along the inner edge, having;r the smaller lag, so that the belt is necessarily caused to accept by and during its use as a quartered belt the above-described curvature into the form ofa segmental band. (Shown by Fig.) The same rounding or curving also appears in step or stair shaped belts being composed of three or more longitudinal strips of unequal breadth-that is to say, when the strips are arranged and connected in su'ch a manner that the overlappings and lags increase from the inner edge Toward the outer edge of the belt.

ln Figs. 4 and 5 I have shown adrivingbelt composed of three longitudinal strips a, b, and c.

'lhe improved belts may also advantageously be employed as crossed belts in connection with conical pulleys, as the conditions above explained with reference to quartered belts also apply in quite a similar manner to crossed belts.

Having thus described my invention, what I claim as new therein, and desire'to secure by Letters Patent, is

1. A driving-belt comprising two or more strips of unequal breadth and stair-shaped in cross-section, substantially as and for the purpose set forth.

2. A driving-belt com posed of two or more strips of unequal breadth and stair-shaped in cross-section, the overlappings and lags of which dier in width, substantially as and for the purpose set forth. 1

3. In a driving-belt, the combination of two or more longitudinal strips of au unequal breadth, connected together to form a belt stair-shaped-in cross section, the overlappings and lags of which increase from the inner edge toward the outer edge of the belt, substantially as and Ifor the purpose set forth.

4. In a driving-belt, the combination of two or more longitudinal strips of unequal breadth, connected together to form a belt stair-shaped in cross-section, the overlappings and lags of which are of unequal breadth, substantially as and for the purpose set forth.

CARL OTTO GEHRGKENS.

lVitnesses:

MAX KAEMPFF, E. H. L. MUMMENHOFF. 

